JP5236734B2 - Lift columns for treatment tables, hospital beds, and care beds - Google Patents

Description

  The present invention relates to a lifting column for a treatment table, a hospital bed and a care bed of the type according to claim 1.

  The hospital bed comprises a lower frame equipped with drive wheels and an upper frame connected to a mattress support. The upper frame can be raised and lowered as a whole to take the desired height from the floor, just as it can be tilted on the horizontal axis (Trendeenburg position). The upper frame can be raised and lowered in various ways, for example, as shown in EP498111B2 by J. Nesbit Evans & Co. Ltd., where the upper frame is connected to the lower frame by a scissor mechanism driven by a linear actuator, for example. It may be obtained at. Another method is to equip the bed with four telescoping legs (see DE29800015U1 from Joh. Stiegelmeyer GmbH & Co. KG). More particularly, the present invention departs from the type of bed in which the upper frame is carried by a single telescopic strut at each end and the strut is fixed to the longitudinal central axis of the lower frame. Structures of this type are shown for example in EP984018A2 from Linet Spol SRO and DE29804283 from Dewert Antriebs-und Systemtechnik GmbH & Co. KG.

  The strength and stiffness requirements for these struts are quite high. Apart from the effects from axial forces, the lifting struts must be able to withstand large torque loads as a result of the large torque loads that result from one or more persons sitting on the edge of the bed. Further, as a result, the torque load appears on the support column in the longitudinal direction of the bed. Trendelenburg adjustment not only creates a torque load when the upper frame tilts, but also creates a longitudinal force on the struts. This also creates a horizontal force on the struts when transporting the bed by manually pushing / pulling the bed's headboard and / or footboard.

  Linak's WO01 / 74198A1 discloses a lifting column that can withstand various considerable forces and torques that occur in such bed structures. The elevating support column includes an encircling and expanding casing having three members, in which three-membered extending and contracting guides each having a lower member, an intermediate member, and an outermost member are housed on both sides. The two intermediate members and the two outermost members are interconnected by a yoke. The intermediate member is extended by a linear actuator located between the two guides and connected to the yoke between the base plate and the two intermediate members. In order to extend the outermost member, a chain drive device in which a chain is arranged around two pulley wheels is provided on both sides. One of the chain lengths is connected to the lower member and the other chain length has a rod connected to the yokes for the two outermost members. The top chain wheels are interconnected and secured to the two intermediate members. This extends the outermost member in synchronism with the extension of the intermediate member. As can be appreciated, the structure is bulky and complex, resulting in high manufacturing costs.

EP498111B2 DE29800015U1 EP984018A2 DE29804283 WO01 / 74198A1

  An object of the present invention is to provide a simplification of such a strut structure.

  This is because in the present invention the three parts of the casing are configured as telescopic guides, which comprise a single body element with one chain and chain wheel, both chain lengths are equipped with drive rods, spindles Is arranged in the cross section of the body element and the spindle nut is fixed to the body element. Thus, there is only one guide that functions as a casing at the same time, so that a compact structure is achieved. Furthermore, there is only one chain, just as the actuator is integral with the body element. In this way, since the column portion is formed with only a few components, the manufacture is further facilitated.

  In an embodiment, the body element has at least one separating end piece to which one of the chain wheels is attached. In a preferred embodiment, the body element has a separate end piece at each end and the chain wheel is attached to these end pieces. This facilitates the assembly process and allows various configurations. The end pieces may be identical so that only one mold is required to produce these end pieces.

  In an embodiment, an adjustment element is located between the end piece and the body element in order to adjust the length between the two chain wheels. It facilitates the assembly process while at the same time allowing the chain to be easily tightened. The adjustment element is preferably configured as a wedge element.

  The spindle nut can be formed directly on the body element, but it has proven to be advantageous to use a separate spindle nut which is preferably embedded in one of the end pieces. This simplifies the production of the body element and at the same time makes it possible to use spindle nuts known per se.

  When the spindle and chain are displaced laterally away from each other, torque is generated in the spindle, which can cause damage to the spindle. This is avoided in embodiments where one end piece is connected to the body element via a tilting shaft so that no torque force can be transmitted to the spindle.

  In order to guide the body element to the side, the body element is placed inside the intermediate telescopic member in the embodiment. The body element is conveniently supported by a notch in the longitudinal rib of the intermediate telescopic member.

  It has proved advantageous to use an electric motor with a length / width ratio of less than 1. As a result, it is possible to provide a slim lifting column.

  In an embodiment, a console for gear and spindle bearings is secured to the front end of the motor so that it appears as a unit for direct attachment to the column.

  The motor length / width ratio shown makes it possible to achieve a slim column while still using a worm drive. Warm drives are attractive because of their high engagement and quietness. The worm wheel is attached to the end of the spindle and the worm is configured as an extension of the motor shaft. The motor is then placed perpendicular to the spindle. When using a commonly used type of motor, it is necessary to place the motor parallel to the spindle, which results in a more complex gear structure.

  In an embodiment, the console has a holder in the form of a pocket in which an elongated printed circuit with at least one end stop switch can be secured. As a result, the printed circuit is parallel to the spindle, and at the same time it can be fixed to the motor unit before it is inserted into the column, thus facilitating assembly.

  The free end of the elongated printed circuit is advantageously equipped with a control device for the upright rod at the lower end of the intermediate member, with an embossment at each end for activating an end stop switch at the end position of the post. This ensures simple control of the column end position. Furthermore, the motor unit can naturally be equipped with an encoder, for example an optical or magnetic encoder, for determining the current length of the column based on the registration of the spindle speed.

  Further features of the present invention will be described in detail with reference to the accompanying drawings in connection with the following description of embodiments of the invention.

1 is a schematic diagram of a hospital bed. It is the side view which looked at the raising / lowering support | pillar in a fully retracted position from the side. It is the side view which looked at the raising / lowering support | pillar in a complete extension position from the side. It is an exploded view of the lifting column. It is an exploded view of a chain unit. It is a side view of a chain unit. It is a longitudinal cross-sectional view of a chain unit. It is a side view of an end piece. FIG. 9 is a cross-sectional view taken along line AA of FIG. FIG. 10 is a sectional view taken along line BB in FIG. 9. It is a perspective view of the end piece of a somewhat different structure. It is sectional drawing of the intermediate member in a raising / lowering support | pillar.

  FIG. 1 of the accompanying drawings shows a schematic diagram of a hospital bed having a lower frame 1 and an upper frame (not shown) equipped with drive wheels. The upper frame is connected to the lower frame 1 by telescopic elevating columns 2 and 3 located at each end of the central axis in the longitudinal direction of the bed. An adjustable base that carries the mattress is embedded in the upper frame. This base has a backrest portion 4 that can be rotated to a raised position about a horizontal axis by a linear actuator 5 (for example, LA31 type of Linak A / S, Denmark). Further, a leg mounting portion 6 that can be similarly adjusted by the linear actuator 7 is provided. There is a fixed intermediate part 8 between the two parts 4, 6. The lifting columns 2, 3 and the two actuators 5, 7 are wire-connected to a control box 9 including a power supply device and a control unit. In order to control the bed, many hand controls 10 are wired to the control box 9, while foot controls can be provided on both sides and staff-specific controls (ACP) can be provided at the foot end of the bed. .

  Figures 2 and 3 of the drawings show the lifting column in the fully retracted and fully extended positions, respectively, from the side. As can be seen, the lifting column has a lower member 11 intended to be attached to the lower frame 1, an intermediate member 12 that can be extended and retracted from the lower member 11, and an intermediate member that extends from the lower member 11. And an outermost member 13 that can be extended from the intermediate member 12 in synchronization with the outermost member 12. Each member is an extruded aluminum tube having a rectangular cross section that itself functions as a locking device that prevents the column from rotating. A plastic slider is placed between the individual parts, which results in partly low friction and partly the production of aluminum tubes when choosing a slider with a thickness that fits the current gap between the tubes. Provides the basis for tolerance equalization. As can be seen from the exploded view of FIG. 4, the base of the lower member 11 is closed by a flat base plate 14. A thread groove is formed in the aluminum tube so that the base plate 14 can be screwed directly to the end. A top frame is fixed to the upper ends of the lower and intermediate members 11 and 12. The top frame, in part, closes the gap between these two members, but also maintains the brick slide in place. A flat top plate 17 that is similarly screwed is fixed to the top of the outermost member 13.

  As can also be seen from FIG. 4, the column comprises a linear actuator 18 with a low voltage reversible DC motor 19 having a gear 20 that drives a spindle 21. This is configured as a unit and is fixedly attached to the underside of the top plate 17 with screws. An elongated end stop circuit is attached to the same unit.

  Further, the column includes the chain unit shown in detail in FIG. 5 of the drawing showing its exploded view and FIGS. 6 and 7 showing the side view and longitudinal section of the chain unit, respectively. The chain unit comprises a body element 22 with an upper separating end piece 23 having a hollow 24 so that it can be loosely fitted onto the end of the elongated body 22 a of the body element 22. The chain wheel 25 with shaft 26 can be inserted into the end piece pocket 27 since the shaft 26 is received in a slot 26a for this purpose. A spindle nut 28 having a spline-coupled first portion rod 29 can be inserted inside the end piece 23, while a well-shaped hole 30 for receiving the spindle nut is formed in the ceiling of the end piece. The well-shaped hole 30 has another part of the spline connection so that the spindle nut 28 is fixed against rotation in the end piece 23. A tubular groove 31 for the spindle 21 and for receiving the spindle nut 28 runs in the axial direction of the body element 22, and the spindle nut with the flange 29 is placed on an extension of the tubular groove 31. The spindle nut 28 is thus fixed in the axial direction between the ceiling of the end piece 23 and the upper edge of the tubular groove 31.

  At the lower end of the body element 22, there is a lower separation end piece 32 having a hollow so that it can be loosely fitted onto the end of the body 22a of the body element. The chain wheel 33 with shaft 34 can be inserted into the pocket 35 of the end piece, since the shaft 34 is received in a slot 36 intended for this purpose. The upper and lower end pieces 23, 32 are identical.

  The lower end 37 of the main body element 22 is curved in a convex shape. Through the opening 38 on the side of the lower end piece 32, an adjustment element 39 can be inserted whose one side 40 has a concave curved shape corresponding to the curved shape of the body 22a of the body element. The body 22a of the body element is thus supported by the hinge joint and otherwise cannot transmit torque to the spindle 21 that could damage the spindle. Torque is generated inter alia as a result of the lateral displacement of the spindle and chain (see below) relative to each other. The opposite side of the adjustment element 39 is configured as a wedge surface 41 and cooperates with a corresponding wedge surface 42 of the hollow ceiling of the lower end piece 22. The wedge surface 41 of the adjustment element 39 has a ridge 43 with a threaded hole 44. Since the screw 46 can be inserted into the hole 45 on the side of the end piece 32, the tension of the adjusting element 39 from the opening 38 can be adjusted, and thus the two wedge surfaces 41, 42 are slid against each other. As it moves, the distance between the two end pieces 23, 32 and thus the distance between the two chain wheels is adjusted.

  The endless chain 47 travels on the two chain wheels 25 and 33 so that the first chain length 48 and the second chain length 49 appear between the two chain wheels, and the first chain length is a drive rod having a hollow. Is fixed to a drive rod 50 having a U-shaped cross section so as to cover the chain. The driving rod 50 has its free end fixed to the outermost member 13. For this purpose, a bushing is inserted at the end of the drive rod so that the drive rod can be fixed to the top plate 17 with screws. A drive rod 51 having a U-shaped cross section is similarly fixed to the other chain length, and its free end is fixed to the lower member 11. The adjustment element 39 also has advantages with respect to assembly. First, the two end pieces 23, 32 are pressed together around the body element 22, the chain 47 is placed on the two chain wheels, and then the adjusting element 39 is inserted to adjust the chain tightening And adjusted.

  Since the trunk | drum 22a of the main body element with a lower end is supported by a hinge, a trunk | drum can tilt sideways. In order to avoid this, the end pieces 23 and 32 have bosses 52 on both sides that mesh with a pair of axial tracks 53 that are arranged to face each other inside the intermediate member 12.

  When the elevating column is started from its fully retracted position, the spindle 21 is screwed to raise the spindle nut 28, and the spindle is fixed to the top plate 17 of the outermost member 13 via the transmission and the motor. Begins to be expelled from the intermediate member 12. Since the chain 47 is fixed to the outermost member 13 together with the drive rod 50, the outermost member is pulled upward, thus moving the chain 47. However, since the chain 47 is fixed to the lower member 11 together with the other drive rod 51, the main body element 22 is pulled upward and starts to drive the intermediate member 12 out of the lower member 11 in synchronization with the outermost member 13.

  Regarding the motor, it is noted that it is a type collaboratively known as an “ABS motor” developed for ABS braking of automobiles, that is, a short small motor. Current motors have a length of only 55 mm and a length / width ratio of 0.78. A substantially cylindrical console 59 with an annular flange 54 having a screw tower for fixing to the top plate 17 with screws is fixed to the front end of the motor.

  The front gear 20 is a worm drive, and the worm wheel is fixed to the end of the spindle 21 just as the bearing is fixed. On one side of the worm wheel is an annular magnet with four magnetic poles. Inserted into the opening of the console 59 is a printed circuit with a Hall element that cooperates with the annular magnet to determine the length of the column based on the rotation of the spindle. On the opposite side of the worm wheel facing the bearing at the end of the spindle, there is a cylindrical part, where a blocking spring of the type described in Linak A / S EP0662573B1 is located, which contributes to the self-locking ability of the spindle . The worm is configured as an extension of the motor shaft, and the free end of the worm is supported by a bearing located on the console wall.

  There is a motor flange 55 extending from the lower end of the console. This flange has a pocket 56 for fixing the elongated printed circuit 57, the upper end of which reaches the inside of the pocket and is fixed by a screw. A guide 57a for the belt-like rod 58 fixed to the base plate 15 of the intermediate member 12 is fixed to the lower end of the printed circuit 57 so as to stand upright vertically and to be guided to the opening of the guide 57a of the printed circuit board. Is done. This printed circuit is equipped with two end stop switches located inside the guide 57a. The end stop switch is activated by embossing at each end of the strip rod 58 to interrupt the motor at the outermost position of the column.

  The console 53 is equipped with a bottom having a hole for the spindle 21. The position of the worm wheel and hence the spindle is determined by the bushing located between the bottom of the console and the bushing on the side of the worm wheel. Therefore, the mutual position of the worm wheel and the worm is also determined.

  As shown, the structure of the column is simple and not only consists of few parts but also easy to assemble. In particular, the struts appear as having a slim design.

Claims (15)

An elevating column for a treatment table, a hospital bed, and a care bed comprising a casing having a casing in which a drive unit is arranged in a hollow space composed of three elastic members (11, 12, 13),
A body element (22) having a chain wheel (25, 33) at each end on which a chain (47) having first and second chain lengths (48, 49) travels between two chain wheels (25, 33) The drive rod (50; 51) is connected to one of the chain lengths (48; 49), and the telescopic members (11, 12, 13) extend or retract from each other depending on the direction of rotation of the motor. The spindle (21) with the spindle nut (28) fixed against rotation due to the longitudinal displacement of the body element (22) with chain wheel (25, 33) via the transmission (20) In the lifting column further comprising a linear actuator (18) with an electric motor (19) to drive,
The three members of the casing are configured as telescopic guides,
It comprises one body element (22) with one chain (47) and chain wheel (25, 33);
Drive rods (50, 51) are provided on both chain lengths (48, 49);
The spindle (21) is located in the cross section of the body element (22) ;
The spindle nut (28) is in the body element (22) ; and
The direction in which the spindle (21) extends is the same as the direction of expansion or contraction of the telescopic member (11, 12, 13);
Lifting strut characterized by.   2. The body element (22) has at least one separating end piece (23, 32), one of the chain wheels (25; 33) being attached to the end piece. The lifting column described in 1.   3. The body element (22) has a separate end piece (23, 32) at each end and the chain wheel (25, 33) is attached to these end pieces. The lifting column described in 1.   Adjustment for adjusting the distance between the two chain wheels (25, 33) to tighten the chain (47) between the end pieces (23, 32) and the rest of the body element (22) Lifting column according to claim 2 or 3, characterized in that an element (39) is present.   Lifting column according to claim 4, characterized in that the adjusting element (39) is a wedge element.   Lifting column according to claim 5, characterized in that the spindle nut is a separation spindle nut (28) embedded in one of the end pieces (23, 32). One of the end pieces (23, 32) is tilted via a tilting shaft so that one of the end pieces (23, 32) and the rest of the body element (22) can tilt relative to each other. Lifting column according to one of claims 2 to 6, characterized in that it is connected to the rest of the body element (22).   The lifting column according to claim 7, characterized in that the body element (22) having the opposite end is placed inside the intermediate telescopic member (12).   Lifting strut according to claim 8, characterized in that the notched body element (22) is guided on a longitudinal groove of the intermediate telescopic member (12).   The body element (22) with two protrusions arranged opposite each other is guided in a pair of longitudinal recesses in the intermediate telescopic member (12) intended for this purpose. The lifting column according to claim 8, characterized in that   Lifting column according to claim 1, characterized in that the motor (19) has a length / width ratio of less than one.   12. Lifting column according to claim 11, characterized in that the front of the motor (19) is equipped with a console for gear and spindle (21) bearings.   The elevating column according to claim 1, wherein the driving device is a worm drive, a worm wheel is attached to an end of the spindle, and the worm is configured as an extension of the motor shaft. 13. Lifting column according to claim 12 , characterized in that said console has a holder in the form of a pocket, in which an elongated printed circuit with at least one end stop switch can be fixed. A rod vertically standing upright from the lower end of the intermediate member (12) at the free end of the elongated printed circuit, the rod having an emboss at each end for activating the end stop switch at the end position of the column 15. Lifting column according to claim 14 , characterized in that there is a guide for

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